linux-stable/kernel
Changbin Du 6a3d4afc54 modules: wait do_free_init correctly
[ Upstream commit 8f8cd6c0a4 ]

The synchronization here is to ensure the ordering of freeing of a module
init so that it happens before W+X checking.  It is worth noting it is not
that the freeing was not happening, it is just that our sanity checkers
raced against the permission checkers which assume init memory is already
gone.

Commit 1a7b7d9220 ("modules: Use vmalloc special flag") moved calling
do_free_init() into a global workqueue instead of relying on it being
called through call_rcu(..., do_free_init), which used to allowed us call
do_free_init() asynchronously after the end of a subsequent grace period.
The move to a global workqueue broke the gaurantees for code which needed
to be sure the do_free_init() would complete with rcu_barrier().  To fix
this callers which used to rely on rcu_barrier() must now instead use
flush_work(&init_free_wq).

Without this fix, we still could encounter false positive reports in W+X
checking since the rcu_barrier() here can not ensure the ordering now.

Even worse, the rcu_barrier() can introduce significant delay.  Eric
Chanudet reported that the rcu_barrier introduces ~0.1s delay on a
PREEMPT_RT kernel.

  [    0.291444] Freeing unused kernel memory: 5568K
  [    0.402442] Run /sbin/init as init process

With this fix, the above delay can be eliminated.

Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com
Fixes: 1a7b7d9220 ("modules: Use vmalloc special flag")
Signed-off-by: Changbin Du <changbin.du@huawei.com>
Tested-by: Eric Chanudet <echanude@redhat.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Xiaoyi Su <suxiaoyi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:31 -04:00
..
bpf bpf: Fix stackmap overflow check on 32-bit arches 2024-03-26 18:21:22 -04:00
cgroup cgroup: Remove duplicates in cgroup v1 tasks file 2023-10-19 23:05:37 +02:00
configs drivers/char: remove /dev/kmem for good 2021-05-07 00:26:34 -07:00
debug kdb: Fix a potential buffer overflow in kdb_local() 2024-01-25 14:52:54 -08:00
dma dma-mapping: clear dev->dma_mem to NULL after freeing it 2024-01-25 14:52:38 -08:00
entry entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up 2023-03-30 12:47:51 +02:00
events perf: Fix the nr_addr_filters fix 2024-02-23 08:54:52 +01:00
futex futex: Don't include process MM in futex key on no-MMU 2023-11-20 11:08:13 +01:00
gcov gcov: add support for checksum field 2022-12-31 13:14:47 +01:00
irq genirq/generic_chip: Make irq_remove_generic_chip() irqdomain aware 2023-11-28 16:56:30 +00:00
kcsan kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures 2023-07-23 13:47:12 +02:00
livepatch livepatch: Fix missing newline character in klp_resolve_symbols() 2023-11-20 11:08:25 +01:00
locking lockdep: Fix block chain corruption 2023-12-03 07:31:23 +01:00
power PM: hibernate: Enforce ordering during image compression/decompression 2024-02-23 08:54:23 +01:00
printk printk: Consolidate console deferred printing 2023-09-23 11:09:59 +02:00
rcu rcu-tasks: Provide rcu_trace_implies_rcu_gp() 2024-03-26 18:21:11 -04:00
sched sched/fair: Take the scheduling domain into account in select_idle_core() 2024-03-26 18:21:15 -04:00
time timekeeping: Fix cross-timestamp interpolation for non-x86 2024-03-26 18:21:15 -04:00
trace bpf: Remove trace_printk_lock 2024-03-01 13:21:43 +01:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-12-31 13:14:40 +01:00
async.c async: Introduce async_schedule_dev_nocall() 2024-02-23 08:54:25 +01:00
audit.c audit: Send netlink ACK before setting connection in auditd_set 2024-02-23 08:54:37 +01:00
audit.h audit: log AUDIT_TIME_* records only from rules 2022-04-08 14:23:06 +02:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-31 17:16:33 +02:00
audit_tree.c audit: move put_tree() to avoid trim_trees refcount underflow and UAF 2021-08-24 18:52:36 -04:00
audit_watch.c audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare() 2023-11-28 16:56:27 +00:00
auditfilter.c
auditsc.c audit: fix possible soft lockup in __audit_inode_child() 2023-09-19 12:22:39 +02:00
backtracetest.c
bounds.c
capability.c
cfi.c cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle 2022-06-22 14:22:04 +02:00
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-04-05 11:24:53 +02:00
configs.c
context_tracking.c
cpu.c hrtimers: Push pending hrtimers away from outgoing CPU earlier 2023-12-13 18:36:31 +01:00
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-08-16 18:55:32 +02:00
crash_core.c kernel/crash_core: suppress unknown crashkernel parameter warning 2021-12-29 12:28:49 +01:00
crash_dump.c
cred.c cred: switch to using atomic_long_t 2023-12-20 15:17:37 +01:00
delayacct.c delayacct: Add sysctl to enable at runtime 2021-05-12 11:43:25 +02:00
dma.c
exec_domain.c
exit.c exit: Use READ_ONCE() for all oops/warn limit reads 2023-02-01 08:27:22 +01:00
extable.c
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-03-11 13:57:38 +01:00
fork.c kernel/fork: beware of __put_task_struct() calling context 2023-09-23 11:09:55 +02:00
freezer.c sched: Add get_current_state() 2021-06-18 11:43:08 +02:00
gen_kheaders.sh kbuild: clean up ${quiet} checks in shell scripts 2021-05-27 04:01:50 +09:00
groups.c
hung_task.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
iomem.c
irq_work.c irq_work: Make irq_work_queue() NMI-safe again 2021-06-10 10:00:08 +02:00
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c kallsyms: Make kallsyms_on_each_symbol generally available 2023-12-13 18:36:45 +01:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
Kconfig.preempt sched/core: Disable CONFIG_SCHED_CORE by default 2021-06-28 22:43:05 +02:00
kcov.c
kexec.c kernel: kexec: copy user-array safely 2023-11-28 16:56:16 +00:00
kexec_core.c kexec: fix a memory leak in crash_shrink_memory() 2023-07-23 13:46:52 +02:00
kexec_elf.c
kexec_file.c kexec: support purgatories with .text.hot sections 2023-06-21 15:59:14 +02:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2023-04-20 12:13:57 +02:00
kheaders.c kheaders: Use array declaration instead of char 2023-05-11 23:00:17 +09:00
kmod.c modules: add CONFIG_MODPROBE_PATH 2021-05-07 00:26:33 -07:00
kprobes.c kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list 2024-01-25 14:52:31 -08:00
ksysfs.c kexec: turn all kexec_mutex acquisitions into trylocks 2023-04-20 12:13:57 +02:00
kthread.c kthread: add the helper function kthread_run_on_cpu() 2023-03-30 12:47:42 +02:00
latencytop.c
Makefile futex: Move to kernel/futex/ 2022-12-31 13:14:04 +01:00
module-internal.h
module.c modules: wait do_free_init correctly 2024-03-26 18:21:31 -04:00
module_signature.c
module_signing.c
notifier.c notifier: Remove atomic_notifier_call_chain_robust() 2021-08-16 18:55:32 +02:00
nsproxy.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
padata.c crypto: pcrypt - Fix hungtask for PADATA_RESET 2023-11-28 16:56:18 +00:00
panic.c exit: Use READ_ONCE() for all oops/warn limit reads 2023-02-01 08:27:22 +01:00
params.c params: lift param_set_uint_minmax to common code 2021-08-16 14:42:22 +02:00
pid.c kernel/pid.c: implement additional checks upon pidfd_create() parameters 2021-08-10 12:53:07 +02:00
pid_namespace.c rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes() 2023-03-10 09:39:09 +01:00
profile.c profiling: fix shift too large makes kernel panic 2022-08-17 14:24:04 +02:00
ptrace.c ptrace: Reimplement PTRACE_KILL by always sending SIGKILL 2022-06-09 10:22:29 +02:00
range.c
reboot.c kernel/reboot: emergency_restart: Set correct system_state 2023-11-28 16:56:31 +00:00
regset.c
relay.c relayfs: fix out-of-bounds access in relay_file_read 2023-05-11 23:00:18 +09:00
resource.c dax/kmem: Fix leak of memory-hotplug resources 2023-03-10 09:40:08 +01:00
resource_kunit.c
rseq.c rseq: Remove broken uapi field layout on 32-bit little endian 2022-04-08 14:23:10 +02:00
scftorture.c scftorture: Forgive memory-allocation failure if KASAN 2023-09-23 11:09:55 +02:00
scs.c scs: Release kasan vmalloc poison in scs_free process 2021-11-18 19:16:29 +01:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2022-02-16 12:56:38 +01:00
signal.c signal handling: don't use BUG_ON() for debugging 2022-07-21 21:24:42 +02:00
smp.c locking/csd_lock: Change csdlock_debug from early_param to __setup 2022-08-17 14:24:24 +02:00
smpboot.c smpboot: Replace deprecated CPU-hotplug functions. 2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c timers/nohz: Last resort update jiffies on nohz_full IRQ entry 2023-08-16 18:22:04 +02:00
stackleak.c gcc-plugins/stackleak: Use noinstr in favor of notrace 2022-02-23 12:03:07 +01:00
stacktrace.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2022-04-13 20:59:28 +02:00
static_call.c static_call: Don't make __static_call_return0 static 2022-04-13 20:59:28 +02:00
static_call_inline.c static_call: Don't make __static_call_return0 static 2022-04-13 20:59:28 +02:00
stop_machine.c
sys.c getrusage: use sig->stats_lock rather than lock_task_sighand() 2024-03-15 10:48:22 -04:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-31 17:16:33 +02:00
sysctl-test.c kernel/sysctl-test: Remove some casts which are no-longer required 2021-06-23 16:41:24 -06:00
sysctl.c sched/rt: Disallow writing invalid values to sched_rt_period_us 2024-03-01 13:21:43 +01:00
task_work.c kasan: record task_work_add() call stack 2021-04-30 11:20:42 -07:00
taskstats.c
test_kprobes.c
torture.c torture: Fix hang during kthread shutdown phase 2023-08-30 16:18:19 +02:00
tracepoint.c tracepoint: Fix kerneldoc comments 2021-08-16 11:39:51 -04:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-01-27 11:05:35 +01:00
ucount.c ucounts: Handle wrapping in is_ucounts_overlimit 2022-02-23 12:03:20 +01:00
uid16.c
uid16.h
umh.c kernel/umh.c: fix some spelling mistakes 2021-05-07 00:26:34 -07:00
up.c A set of locking related fixes and updates: 2021-05-09 13:07:03 -07:00
user-return-notifier.c
user.c fs/epoll: use a per-cpu counter for user's watches count 2021-09-08 11:50:27 -07:00
user_namespace.c ucounts: Fix systemd LimitNPROC with private users regression 2022-03-08 19:12:42 +01:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname.c
utsname_sysctl.c
watch_queue.c kernel: watch_queue: copy user-array safely 2023-11-28 16:56:16 +00:00
watchdog.c watchdog: move softlockup_panic back to early_param 2023-11-28 16:56:28 +00:00
watchdog_hld.c watchdog/perf: more properly prevent false positives with turbo modes 2023-07-23 13:46:52 +02:00
workqueue.c Revert "workqueue: remove unused cancel_work()" 2023-12-08 08:48:03 +01:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00